Authorities investigate a shooting in the parking lot of the Twin Peaks restaurant Sunday, May 17, 2015, in Waco, Texas. Authorities say that the shootout victims were members of rival biker gangs that had gathered for a meeting. (AP Photo/Jerry Larson) ( Waco Shooting )

People stand as officers investigate a shooting in the parking lot of the Twin Peaks restaurant Sunday, May 17, 2015, in Waco, Texas. Authorities say that the shootout victims were members of rival biker gangs that had gathered for a meeting. (AP Photo/Jerry Larson) ( Waco Shooting )